1 /*
2  * Copyright (C) 2006 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 //
18 // Zip archive entries.
19 //
20 // The ZipEntry class is tightly meshed with the ZipFile class.
21 //
22 #ifndef __LIBS_ZIPENTRY_H
23 #define __LIBS_ZIPENTRY_H
24 
25 #include <stdlib.h>
26 #include <stdint.h>
27 #include <stdio.h>
28 
29 typedef int status_t;
30 
31 namespace android {
32 
33 class ZipFile;
34 
35 /*
36  * ZipEntry objects represent a single entry in a Zip archive.
37  *
38  * File information is stored in two places: next to the file data (the Local
39  * File Header, and possibly a Data Descriptor), and at the end of the file
40  * (the Central Directory Entry).  The two must be kept in sync.
41  */
42 class ZipEntry {
43 public:
44     friend class ZipFile;
45 
ZipEntry(void)46     ZipEntry(void) {}
~ZipEntry(void)47     ~ZipEntry(void) {}
48 
49     /*
50      * Some basic functions for raw data manipulation.  "LE" means
51      * Little Endian.
52      */
getShortLE(const uint8_t * buf)53     static inline uint16_t getShortLE(const uint8_t* buf) {
54         return buf[0] | (buf[1] << 8);
55     }
getLongLE(const uint8_t * buf)56     static inline uint32_t getLongLE(const uint8_t* buf) {
57         return buf[0] | (buf[1] << 8) | (buf[2] << 16) | (buf[3] << 24);
58     }
putShortLE(uint8_t * buf,uint16_t val)59     static inline void putShortLE(uint8_t* buf, uint16_t val) {
60         buf[0] = (uint8_t) val;
61         buf[1] = (uint8_t) (val >> 8);
62     }
63 
64 protected:
65     /*
66      * Initialize the structure from the file, which is pointing at
67      * our Central Directory entry. And rewrite it.
68      */
69     status_t initAndRewriteFromCDE(FILE* fp);
70 
71 private:
72     /* these are private and not defined */
73     ZipEntry(const ZipEntry& src);
74     ZipEntry& operator=(const ZipEntry& src);
75 
76     /*
77      * Every entry in the Zip archive starts off with one of these.
78      */
79     class LocalFileHeader {
80     public:
LocalFileHeader(void)81         LocalFileHeader(void) {}
82 
83         status_t rewrite(FILE* fp);
84 
85         enum {
86             kSignature      = 0x04034b50,
87             kLFHLen         = 30,       // LocalFileHdr len, excl. var fields
88         };
89     };
90 
91     /*
92      * Every entry in the Zip archive has one of these in the "central
93      * directory" at the end of the file.
94      */
95     class CentralDirEntry {
96     public:
CentralDirEntry(void)97         CentralDirEntry(void) :
98             mLocalHeaderRelOffset(0)
99         {}
100 
101         status_t rewrite(FILE* fp);
102 
103         uint32_t mLocalHeaderRelOffset;
104 
105         enum {
106             kSignature      = 0x02014b50,
107             kCDELen         = 46,       // CentralDirEnt len, excl. var fields
108         };
109     };
110 
111     LocalFileHeader     mLFH;
112     CentralDirEntry     mCDE;
113 };
114 
115 }; // namespace android
116 
117 #endif // __LIBS_ZIPENTRY_H
118